Mařenka has fallen in love with a young man, Jeniík, a stranger to her village. Driven away from his family home at an early age by his jealous stepmother, Jeník was forced to join the army and is now, some years later, working as a farmhand. Mařenka's father, Krušina, owes a substantial sum of money to a man called Tobiáš Mícha. The local mayor, Kecal, has negotiated an agreement whereby the debt will be cancelled if Krušina agrees to the marriage of his daughter with Tobiáš Mícha's son.
The villagers are preparing to celebrate a national holiday. Mařenka has just learnt of the imminent arrival of Vasšk, the man her father wants her to marry. She is determined to refuse him and marry Jeniík.
Kecal reminds Mařenka's parents, Krušina and Ludmila, of the arrangement made with Tobiáš Mícha, insisting that the marriage should go ahead, even through no-one has yet met the proposed bridegroom. Ludmila wants Mařenka to be able to make her own choice. Kecal attempts to secure Mařenka's agreement to the marriage but she is not to be persuaded.
Mařenka comes across the bewildered, timid Vašek. Without revealing who she is, she manages to paint such a terrifying picture of Mařenka, his intended bride, that he swears he will never marry her.
Kecal tries to tempt Jeník to give up Mařenka by offering him another marriage prospect. As he listens to Kecal, Jeník notes that the husband proposed for Mařenka is stipulated as being 'the song of Tobiáš Mícha.' Spotting a loophole, he agrees to renounce Mařenka in return for a cash lump sum but only on condition that she does indeed marry the son of Tobiáš Mícha and that Krušina is freed of his debt.
Once he is alone, Jeník reaffirms his love for Mařenka. However, when Kecal returns with a group of villagers as witnesses, he rejects her publicly in return for the money. The villagers are shocked by his callous and mercenary attitude.
Vašek is still worried about the woman that his parents want him to marry but he is distracted by the arrival of a travelling circus troupe. He becomes entranced by their star performer, Esmeralda. When the circus manager learns that the performer who normally plays the dancing bear is too drunk to be entrusted with the role, he and Esmeralda persuade Vašek to take his place.
Mícha and his wife Háta come with Kecal to make the final arrangements for the marriage and are outraged by Vašek's refusal to proceed. When Mařenka and her parents arrive, she is forcsed to confront the fact that Jeník has sold her. Distraught, she asks to be given a little time to think. Her anger increases when Jeník refuses to deny his involvement with the transaction.
When the villagers arrive to hear Mařenka's decision, Jeník reveals his identity as the eldest son of Tobiáš Mícha, claiming his bride under the strict terms of the contract. Kecal has been outwitted and the villagers turn against him for his bullying and manipulative behaviour.
Reconciled with his son, Mícha gives his blessing to the marriage of Mařenka and Jeník.